none For the aim of this two-years project, in 1991 and 1992 were investigated habits, biology and parasitoid-complex of the Diprionid-species Monoctenus juniperi (L). (Hym., Symphyta). The material originates from 4 stations of N-Tyrol (Austria): Gnadenwald (GW, 800 m), Zimmerberg (ZB, 750 - 900 m), Otztal Eingang (OE, 700 - 800 m), Kuhtai (KH, 2020 m). Collections were carried out "beating" Juniperus communis L. and its ssp. nana SYME bushes (beating-time required per collection-date, station and person: 15 min). Altogether in 1991 1115 larvae and 92 adults were captured, in 1992 1426 larvae and 41 adults. The flying-period of adults lasted from May till mid-June, at the higher station Kuhtai from the end of June till mid-July; this seems to occur contemporaneously with the juniper's flowering-period. The oviposition occurs more likely into the young needles. The eggs are not covered with froth; their average size is 1.5 mm x 0.39 mm. The lightgreen, 3-striped larvae were kept in plastic-boxes on juniper-twigs; they will be achieved the 5th stage ( female female ), whereas they will be after the 4th stage entered on the praepupa-stage ( male male ). The cocoons length resulted different between the two sexes. The larvae can be find on juniper's needles from mid-/-late June till early/mid-September. At Kuhtai the larval phenology results deferred: larvae were collected from mid-July till even the beginning of October. The feed-way, the stages-sequence and the width of the head-capsule were also investigated. References to a prolonged diapause weren't found. Investigations about the eggs-parasitoids were without results. Larvae, on the contrary, were befallen especially by the Tachinid Staurochaeta albocingulata FALL. and by the Ichneumonid Lamachus sp. (very probably L. dispar HTG) and Exenterus ictericus (GRAV.). In 2 specimens slipped out the unspecific Tachinid Drino inconspicua MEIG. too. Particular was the attack of Nematods (family Mermithidae, genus Hexamermis). On the contrary any parasitoids slipped out from cocoons, that were exposed at the two stations (GW, OE). The Hetereoptere Rhinocoris annulatum L. was identified as predator of M. juniperi-larvae among the insects.